1
|
Loewen MA, Sertich JJW, Sampson S, O’Connor JK, Carpenter S, Sisson B, Øhlenschlæger A, Farke AA, Makovicky PJ, Longrich N, Evans DC. Lokiceratops rangiformis gen. et sp. nov. (Ceratopsidae: Centrosaurinae) from the Campanian Judith River Formation of Montana reveals rapid regional radiations and extreme endemism within centrosaurine dinosaurs. PeerJ 2024; 12:e17224. [PMID: 38912046 PMCID: PMC11193970 DOI: 10.7717/peerj.17224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 03/20/2024] [Indexed: 06/25/2024] Open
Abstract
The Late Cretaceous of western North America supported diverse dinosaur assemblages, though understanding patterns of dinosaur diversity, evolution, and extinction has been historically limited by unequal geographic and temporal sampling. In particular, the existence and extent of faunal endemism along the eastern coastal plain of Laramidia continues to generate debate, and finer scale regional patterns remain elusive. Here, we report a new centrosaurine ceratopsid, Lokiceratops rangiformis, from the lower portion of the McClelland Ferry Member of the Judith River Formation in the Kennedy Coulee region along the Canada-USA border. Dinosaurs from the same small geographic region, and from nearby, stratigraphically equivalent horizons of the lower Oldman Formation in Canada, reveal unprecedented ceratopsid richness, with four sympatric centrosaurine taxa and one chasmosaurine taxon. Phylogenetic results show that Lokiceratops, together with Albertaceratops and Medusaceratops, was part of a clade restricted to a small portion of northern Laramidia approximately 78 million years ago. This group, Albertaceratopsini, was one of multiple centrosaurine clades to undergo geographically restricted radiations, with Nasutuceratopsini restricted to the south and Centrosaurini and Pachyrostra restricted to the north. High regional endemism in centrosaurs is associated with, and may have been driven by, high speciation rates and diversity, with competition between dinosaurs limiting their geographic range. High speciation rates may in turn have been driven in part by sexual selection or latitudinally uneven climatic and floral gradients. The high endemism seen in centrosaurines and other dinosaurs implies that dinosaur diversity is underestimated and contrasts with the large geographic ranges seen in most extant mammalian megafauna.
Collapse
Affiliation(s)
- Mark A. Loewen
- Natural History Museum of Utah, Salt Lake City, UT, United States of America
- Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah, United States of America
- Evolutionsmuseet, Knuthenborg, Maribo, Denmark
| | - Joseph J. W. Sertich
- Evolutionsmuseet, Knuthenborg, Maribo, Denmark
- Smithsonian Tropical Research Institute, Panama City, Panamá
- Department of Geosciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Scott Sampson
- California Academy of Sciences, San Francisco, California, United States of America
| | | | - Savhannah Carpenter
- Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah, United States of America
| | - Brock Sisson
- Independent Researcher, Pleasant Grove, Utah, United States of America
| | | | - Andrew A. Farke
- Raymond M. Alf Museum of Paleontology, Claremont, California, United States of America
| | - Peter J. Makovicky
- Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Nick Longrich
- Department of Life Sciences, University of Bath, Bath, United Kingdom
| | - David C. Evans
- Department of Natural History, Royal Ontario Museum, Toronto, Ontario, Canada
- Department of Ecology and Evolution, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
2
|
Alarcón-Muñoz J, Vargas AO, Püschel HP, Soto-Acuña S, Manríquez L, Leppe M, Kaluza J, Milla V, Gutstein CS, Palma-Liberona J, Stinnesbeck W, Frey E, Pino JP, Bajor D, Núñez E, Ortiz H, Rubilar-Rogers D, Cruzado-Caballero P. Relict duck-billed dinosaurs survived into the last age of the dinosaurs in subantarctic Chile. SCIENCE ADVANCES 2023; 9:eadg2456. [PMID: 37327335 PMCID: PMC10275600 DOI: 10.1126/sciadv.adg2456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 05/11/2023] [Indexed: 06/18/2023]
Abstract
In the dusk of the Mesozoic, advanced duck-billed dinosaurs (Hadrosauridae) were so successful that they likely outcompeted other herbivores, contributing to declines in dinosaur diversity. From Laurasia, hadrosaurids dispersed widely, colonizing Africa, South America, and, allegedly, Antarctica. Here, we present the first species of a duck-billed dinosaur from a subantarctic region, Gonkoken nanoi, of early Maastrichtian age in Magallanes, Chile. Unlike duckbills further north in Patagonia, Gonkoken descends from North American forms diverging shortly before the origin of Hadrosauridae. However, at the time, non-hadrosaurids in North America had become replaced by hadrosaurids. We propose that the ancestors of Gonkoken arrived earlier in South America and reached further south, into regions where hadrosaurids never arrived: All alleged subantarctic and Antarctic remains of hadrosaurids could belong to non-hadrosaurid duckbills like Gonkoken. Dinosaur faunas of the world underwent qualitatively different changes before the Cretaceous-Paleogene asteroid impact, which should be considered when discussing their possible vulnerability.
Collapse
Affiliation(s)
- Jhonatan Alarcón-Muñoz
- Red Paleontológica U-Chile, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- Área Paleontología, Museo Nacional de Historia Natural de Chile, Santiago, Chile
| | - Alexander O. Vargas
- Red Paleontológica U-Chile, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Hans P. Püschel
- Red Paleontológica U-Chile, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- School of GeoSciences, University of Edinburgh, Grant Institute, Edinburgh, UK
| | - Sergio Soto-Acuña
- Red Paleontológica U-Chile, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- KayTreng Consultores SpA, Ñuñoa, Santiago, Chile
- Escuela de Geología, Facultad de Ciencias, Universidad Mayor, Manuel Montt 367, Providencia, Santiago, Chile
| | | | - Marcelo Leppe
- Laboratorio de Paleobiología, Instituto Nacional Antártico Chileno, Punta Arenas, Chile
| | - Jonatan Kaluza
- Fundación Félix de Azara, Argentina, CONICET, Buenos Aires, Argentina
| | - Verónica Milla
- Red Paleontológica U-Chile, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- Universidad de Concepción, Concepción, Chile
| | - Carolina S. Gutstein
- Red Paleontológica U-Chile, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- Paleo Consultores, Pedro de Valdivia 273, Providencia 1602, Chile
| | - José Palma-Liberona
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Wolfgang Stinnesbeck
- Institut für Geowissenschaften, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 234-236, Heidelberg 69120, Germany
| | - Eberhard Frey
- Staatliches Museum für Naturkunde Karlsruhe (SMNK), Erbprinzenstraße 13, Karlsruhe 76133, Germany
| | - Juan Pablo Pino
- Red Paleontológica U-Chile, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Dániel Bajor
- Red Paleontológica U-Chile, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Elaine Núñez
- Red Paleontológica U-Chile, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Héctor Ortiz
- Red Paleontológica U-Chile, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- Universidad de Magallanes, Punta Arenas, Chile
| | - David Rubilar-Rogers
- Área Paleontología, Museo Nacional de Historia Natural de Chile, Santiago, Chile
| | - Penélope Cruzado-Caballero
- Área de Paleontología, Departamento de Biología Animal, Edafología y Geología, Universidad de La Laguna, Tenerife, Spain
- Grupo Aragosaurus-IUCA, Facultad de Ciencias, Universidad de Zaragoza, Zaragoza, Spain
| |
Collapse
|
3
|
Warshaw EA, Fowler DW. A transitional species of Daspletosaurus Russell, 1970 from the Judith River Formation of eastern Montana. PeerJ 2022; 10:e14461. [PMID: 36452080 PMCID: PMC9703990 DOI: 10.7717/peerj.14461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 11/03/2022] [Indexed: 11/27/2022] Open
Abstract
Here we describe a new derived tyrannosaurine, Daspletosaurus wilsoni sp. nov., from Judithian strata (~76.5 Ma) intermediate in age between either of the previously described species of this genus. D. wilsoni displays a unique combination of ancestral and derived characteristics, including a cornual process of the lacrimal reduced in height relative to D. torosus and more basal tyrannosaurines, and a prefrontal with a long axis oriented more rostrally than in D. horneri and more derived tyrannosaurines. The description of this taxon provides insight into evolutionary mode in Tyrannosaurinae, lending strength to previous hypotheses of anagenesis within Daspletosaurus and increasing the resolution with which the evolution of this lineage can be reconstructed. Cladistic phylogenetic methods, stratigraphy, and qualitative analysis of the morphology of relevant taxa supports an anagenetic model for the origin of morphological novelty in this genus, highlighting the predominance of anagenetic evolution among contemporary dinosaur lineages.
Collapse
Affiliation(s)
- Elías A. Warshaw
- Badlands Dinosaur Museum, Dickinson, North Dakota, United States,Department of Earth Sciences, Montana State University, Bozeman, MT, United States
| | - Denver W. Fowler
- Badlands Dinosaur Museum, Dickinson, North Dakota, United States
| |
Collapse
|
4
|
Takasaki R, Chiba K, Fiorillo AR, Brink KS, Evans DC, Fanti F, Saneyoshi M, Maltese A, Ishigaki S. Description of the first definitive
Corythosaurus
(Dinosauria, Hadrosauridae) specimens from the Judith River Formation in Montana, USA and their paleobiogeographical significance. Anat Rec (Hoboken) 2022. [DOI: 10.1002/ar.25097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/31/2022] [Accepted: 08/29/2022] [Indexed: 11/08/2022]
Affiliation(s)
- Ryuji Takasaki
- Faculty of Biosphere‐Geosphere Science Okayama University of Science Okayama Japan
| | - Kentaro Chiba
- Faculty of Biosphere‐Geosphere Science Okayama University of Science Okayama Japan
| | - Anthony R. Fiorillo
- The New Mexico Museum of Natural History & Science Albuquerque New Mexico USA
| | - Kirstin S. Brink
- Department of Earth Sciences University of Manitoba Manitoba Canada
| | | | - Federico Fanti
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali Alma Mater Studiorum, Universita di Bologna Bologna Italy
| | - Mototaka Saneyoshi
- Faculty of Biosphere‐Geosphere Science Okayama University of Science Okayama Japan
| | - Anthony Maltese
- Rocky Mountain Dinosaur Resource Center Woodland Park Colorado USA
| | - Shinobu Ishigaki
- Faculty of Biosphere‐Geosphere Science Okayama University of Science Okayama Japan
| |
Collapse
|
5
|
Wosik M, Evans DC. Osteohistological and taphonomic life-history assessment of Edmontosaurus annectens (Ornithischia: Hadrosauridae) from the Late Cretaceous (Maastrichtian) Ruth Mason dinosaur quarry, South Dakota, United States, with implication for ontogenetic segregation between juvenile and adult hadrosaurids. J Anat 2022; 241:272-296. [PMID: 35801524 PMCID: PMC9296034 DOI: 10.1111/joa.13679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 11/28/2022] Open
Abstract
The Late Cretaceous (Maastrichtian) Ruth Mason Dinosaur Quarry (RMDQ) represents a monodominant Edmontosaurus annectens bonebed from the Hell Creek Formation of South Dakota and has been determined as a catastrophic death assemblage likely belonging to a single population, providing an ideal sample to investigate hadrosaurid growth and population dynamics. For this study, size-frequency distributions were constructed from linear measurements of long bones (humeri, femora, tibiae) from RMDQ that revealed five relatively distinct size classes along a generally right-skewed distribution, which is consistent with a catastrophic assemblage. To test the relationship between morphological size ranges and ontogenetic age classes, subsets from each size-frequency peak were transversely thin-sectioned at mid-diaphysis to conduct an ontogenetic age assessment based on growth marks and observations of the bone microstructure. When combining these independent datasets, growth marks aligned with size-frequency peaks, with the exclusion of the overlapping subadult-adult size range, indicating a strong size-age relationship in early ontogeny. A growth curve analysis of tibiae indicated that E. annectens exhibited a similar growth trajectory to the Campanian hadrosaurid Maiasaura, although attaining a much larger asymptotic body size by about 9 years of age, further suggesting that the clade as a whole may have inherited a similar growth strategy. This rich new dataset for E. annectens provides new perspectives on other hypotheses of hadrosaurid life history. When the RMDQ population was compared with size distributions from other hadrosaurid bonebed assemblages, juveniles (categorized as ages one and two) were either completely absent from or heavily underrepresented in the samples, providing support for the hypothesized segregation between juvenile and adult hadrosaurids. Osteohistological comparison with material from polar and temperate populations of Edmontosaurus revealed that previous conclusions correlating osteohistological growth patterns with the strength of environmental stressors were a result of sampling non-overlapping ontogenetic growth stages.
Collapse
Affiliation(s)
- Mateusz Wosik
- Department of BiologyMisericordia UniversityDallasPennsylvaniaUSA
- Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoOntarioCanada
- Department of Natural History, Royal Ontario MuseumTorontoOntarioCanada
| | - David C. Evans
- Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoOntarioCanada
- Department of Natural History, Royal Ontario MuseumTorontoOntarioCanada
| |
Collapse
|
6
|
Madzia D, Arbour VM, Boyd CA, Farke AA, Cruzado-Caballero P, Evans DC. The phylogenetic nomenclature of ornithischian dinosaurs. PeerJ 2021; 9:e12362. [PMID: 34966571 PMCID: PMC8667728 DOI: 10.7717/peerj.12362] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 09/30/2021] [Indexed: 11/25/2022] Open
Abstract
Ornithischians form a large clade of globally distributed Mesozoic dinosaurs, and represent one of their three major radiations. Throughout their evolutionary history, exceeding 134 million years, ornithischians evolved considerable morphological disparity, expressed especially through the cranial and osteodermal features of their most distinguishable representatives. The nearly two-century-long research history on ornithischians has resulted in the recognition of numerous diverse lineages, many of which have been named. Following the formative publications establishing the theoretical foundation of phylogenetic nomenclature throughout the 1980s and 1990s, many of the proposed names of ornithischian clades were provided with phylogenetic definitions. Some of these definitions have proven useful and have not been changed, beyond the way they were formulated, since their introduction. Some names, however, have multiple definitions, making their application ambiguous. Recent implementation of the International Code of Phylogenetic Nomenclature (ICPN, or PhyloCode) offers the opportunity to explore the utility of previously proposed definitions of established taxon names. Since the Articles of the ICPN are not to be applied retroactively, all phylogenetic definitions published prior to its implementation remain informal (and ineffective) in the light of the Code. Here, we revise the nomenclature of ornithischian dinosaur clades; we revisit 76 preexisting ornithischian clade names, review their recent and historical use, and formally establish their phylogenetic definitions. Additionally, we introduce five new clade names: two for robustly supported clades of later-diverging hadrosaurids and ceratopsians, one uniting heterodontosaurids and genasaurs, and two for clades of nodosaurids. Our study marks a key step towards a formal phylogenetic nomenclature of ornithischian dinosaurs.
Collapse
Affiliation(s)
- Daniel Madzia
- Department of Evolutionary Paleobiology, Institute of Paleobiology, Polish Academy of Sciences, Warsaw, Poland
| | - Victoria M. Arbour
- Department of Knowledge, Royal BC Museum, Victoria, BC, Canada
- School of Earth and Ocean Sciences, University of Victoria, Victoria, BC, Canada
| | | | - Andrew A. Farke
- Raymond M. Alf Museum of Paleontology at The Webb Schools, Claremont, CA, USA
| | - Penélope Cruzado-Caballero
- Área de Paleontología, Departamento de Biología Animal, Edafología y Geología, Universidad de La Laguna, Santa Cruz de Tenerife, Spain
- Instituto de Investigación en Paleobiología y Geología (IIPG), Universidad Nacional de Río Negro (UNRN), Río Negro, Argentina
- Instituto de Investigación en Paleobiología y Geología (IIPG), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Río Negro, Argentina
- Grupo Aragosaurus-IUCA, Área de Paleontología, Departamento de Ciencias de la Tierra, Universidad de Zaragoza, Zaragoza, Spain
| | - David C. Evans
- Department of Natural History, Royal Ontario Museum, Toronto, ON, Canada
| |
Collapse
|
7
|
Chiarenza AA, Fabbri M, Consorti L, Muscioni M, Evans DC, Cantalapiedra JL, Fanti F. An Italian dinosaur Lagerstätte reveals the tempo and mode of hadrosauriform body size evolution. Sci Rep 2021; 11:23295. [PMID: 34857789 PMCID: PMC8640049 DOI: 10.1038/s41598-021-02490-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 11/17/2021] [Indexed: 02/07/2023] Open
Abstract
During the latest Cretaceous, the European Archipelago was characterized by highly fragmented landmasses hosting putative dwarfed, insular dinosaurs, claimed as fossil evidence of the “island rule”. The Villaggio del Pescatore quarry (north-eastern Italy) stands as the most informative locality within the palaeo-Mediterranean region and represents the first, multi-individual Konservat-Lagerstätte type dinosaur-bearing locality in Italy. The site is here critically re-evaluated as early Campanian in age, thus preceding the final fragmentation stages of the European Archipelago, including all other European localities preserving hypothesized dwarfed taxa. New skeletal remains allowed osteohistological analyses on the hadrosauroid Tethyshadros insularis indicating subadult features in the type specimen whereas a second, herein newly described, larger individual is likely somatically mature. A phylogenetic comparative framework places the body-size of T. insularis in range with other non-hadrosaurid Eurasian hadrosauroids, rejecting any significant evolutionary trend towards miniaturisation in this clade, confuting its ‘pygmy’ status, and providing unmatched data to infer environmentally-driven body-size trends in Mesozoic dinosaurs.
Collapse
Affiliation(s)
| | - Matteo Fabbri
- Field Museum of Natural History, Chicago, IL, 60605, USA
| | - Lorenzo Consorti
- Department of Mathematics and Geosciences, University of Trieste, 34128, Trieste, Italy.,Geological Survey of Italy (ISPRA), 00144, Rome, Italy
| | - Marco Muscioni
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Alma Mater Studiorum, Università Di Bologna, 40126, Bologna, Italy
| | - David C Evans
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, M5S 3B2, Canada.,Department of Natural History, Royal Ontario Museum, Toronto, ON, M5S 2C6, Canada
| | - Juan L Cantalapiedra
- GloCEE-Global Change Ecology and Evolution Research Group, Departamento de Ciencias de la Vida, Universidad de Alcalá, 28801, Alcalá de Henares, Spain
| | - Federico Fanti
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Alma Mater Studiorum, Università Di Bologna, 40126, Bologna, Italy
| |
Collapse
|
8
|
Doran Brownstein C. Dinosaurs from the Santonian-Campanian Atlantic coastline substantiate phylogenetic signatures of vicariance in Cretaceous North America. ROYAL SOCIETY OPEN SCIENCE 2021; 8:210127. [PMID: 34457333 PMCID: PMC8385347 DOI: 10.1098/rsos.210127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 08/02/2021] [Indexed: 06/13/2023]
Abstract
During the Cretaceous, diversifications and turnovers affected terrestrial vertebrates experiencing the effects of global geographical change. However, the poor fossil record from the early Late Cretaceous has concealed how dinosaurs and other terrestrial vertebrates responded to these events. I describe two dinosaurs from the Santonian to Early Campanian of the obscure North American paleolandmass Appalachia. A revised look at a large, potentially novel theropod shows that it likely belongs to a new clade of tyrannosauroids solely from Appalachia. Another partial skeleton belongs to an early member of the Hadrosauridae, a highly successful clade of herbivorous dinosaurs. This skeleton is associated with the first small juvenile dinosaur specimens from the Atlantic Coastal Plain. The tyrannosauroid and hadrosaurid substantiate one of the only Late Santonian dinosaur faunas and help pinpoint the timing of important anatomical innovations in two widespread dinosaur lineages. The phylogenetic positions of the tyrannosauroid and hadrosaurid show Santonian Appalachian dinosaur faunas are comparable to coeval Eurasian ones, and the presence of clades formed only by Appalachian dinosaur taxa establishes a degree of endemism in Appalachian dinosaur assemblages attributable to episodes of vicariance.
Collapse
Affiliation(s)
- Chase Doran Brownstein
- Stamford Museum and Nature Center, Stamford, CT, USA
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA
| |
Collapse
|
9
|
Kobayashi Y, Takasaki R, Kubota K, Fiorillo AR. A new basal hadrosaurid (Dinosauria: Ornithischia) from the latest Cretaceous Kita-ama Formation in Japan implies the origin of hadrosaurids. Sci Rep 2021; 11:8547. [PMID: 33903622 PMCID: PMC8076177 DOI: 10.1038/s41598-021-87719-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 04/01/2021] [Indexed: 11/21/2022] Open
Abstract
Here we describe a partial hadrosaurid skeleton from the marine Maastrichtian Kita-ama Formation in Japan as a new taxon, Yamatosaurus izanagii gen. et sp. nov., based on unique characters in the dentition. Our phylogenetic analysis demonstrates Yamatosaurus izanagii belongs to Hadrosauridae, composed of Hadrosaurus foulkii + (Yamatosaurus izanagii + (Saurolophinae + Lambeosaurinae)). The coracoid lacks a biceps tubercle as in non-hadrosaurid hadrosauroids, suggesting its presence is a key feature for the clade of Saurolophinae and Lambeosaurinae. The evolutionary rates analysis further supports that shoulder and forelimb features, which are likely to have been involved in locomotion, were important for the early evolution of Hadrosauridae. Our biogeographic analyses show that basal hadrosaurids were widely distributed in Asia and Appalachia, that the clade of Saurolophinae and Lambeosaurinae originated in Asia, and that eastern Asia may have served as a refugium of relict hadrosauroid taxa such as Plesiohadros djadokhtaensis, Tanius sinensis, and Yamatosaurus izanagii during the Late Cretaceous. The contemporaneous occurrence of basal (Yamatosaurus izanagii) and derived (Kamuysaurus japonicus) hadrosaurids during the Maastrichtian in Japan is the first record in Asia. Because of the long geographical distance between these localities, they likely did not co-exist, but instead demonstrate some level of provinciality.
Collapse
Affiliation(s)
- Yoshitsugu Kobayashi
- Hokkaido University Museum, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan.
| | - Ryuji Takasaki
- Faculty of Biosphere-Geosphere Science, Okayama University of Science, Okayama, 700-0005, Japan
| | - Katsuhiro Kubota
- Hokkaido University Museum, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan
- Museum of Nature and Human Activities, Hyogo, Sanda, Hyogo, 669-1546, Japan
- Institute of Natural and Environmental Sciences, University of Hyogo, Sanda, Hyogo, 669-1546, Japan
| | - Anthony R Fiorillo
- Hokkaido University Museum, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan
- Institute for the Study of Earth and Man, Southern Methodist University, Dallas, TX, 75275, USA
| |
Collapse
|
10
|
McDonald AT, Wolfe DG, Freedman Fowler EA, Gates TA. A new brachylophosaurin (Dinosauria: Hadrosauridae) from the Upper Cretaceous Menefee Formation of New Mexico. PeerJ 2021; 9:e11084. [PMID: 33859873 PMCID: PMC8020878 DOI: 10.7717/peerj.11084] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 02/18/2021] [Indexed: 11/20/2022] Open
Abstract
Brachylophosaurini is a clade of hadrosaurid dinosaurs from the Campanian of western North America. Although well-known from northern localities in Montana and Alberta, including abundant material of Brachylophosaurus canadensis and Maiasaura peeblesorum and the holotypes of Acristavus gagslarsoni and Probrachylophosaurus bergei, material from southern localities in Utah and Colorado is restricted to a partial skull referred to A. gagslarsoni and several indeterminate specimens. Here we describe Ornatops incantatus gen. et sp. nov., a new brachylophosaurin known from a partial skeleton from the Allison Member of the Menefee Formation in New Mexico. Ornatops is the first brachylophosaurin reported from New Mexico and the southernmost occurrence of the clade. Ornatops shares with Probrachylophosaurus and Brachylophosaurus a caudally expanded nasofrontal suture on the frontals, but also exhibits an autapomorphic nasofrontal suture morphology, with a horizontal rostral region and elevated caudal region with two prominent parasagittal bumps, which is different from other brachylophosaurin specimens, including juvenile and adult Brachylophosaurus. A phylogenetic analysis places Ornatops in a trichotomy with Probrachylophosaurus and Brachylophosaurus, with Maiasaura and Acristavus as successive outgroups.
Collapse
Affiliation(s)
| | | | | | - Terry A. Gates
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA
| |
Collapse
|
11
|
Brownstein CD. Osteology and phylogeny of small-bodied hadrosauromorphs from an end-Cretaceous marine assemblage. Zool J Linn Soc 2021. [DOI: 10.1093/zoolinnean/zlaa085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
The timing of non-avian dinosaur decline is one of the most debated subjects in dinosaur palaeontology. Dinosaur faunas from the last few million years of the Mesozoic appear far less diverse than those from earlier in the Cretaceous, a trend that could suggest non-avian dinosaur extinction occurred gradually. However, the limited nature of the latest Cretaceous dinosaur record outside western North America has obscured patterns in dinosaur diversity just before the extinction. Here, I describe two associated skeletons and several isolated fossils recovered from the New Egypt Formation of New Jersey, a latest Maastrichtian unit that underlies the K–Pg boundary. The larger skeleton appears to be a small-bodied adult from a lineage outside Hadrosauridae, the dominant group of these animals during the Maastrichtian, that persisted along the eastern coast of North America. Smaller specimens are identifiable as juvenile hadrosauromorphs. These results substantiate an important assemblage of herbivorous dinosaurs from the poorly-known Cretaceous of eastern North America. The marine depositional setting for these skeletons demonstrates that proposed ecosystem preferences among hadrosauromorphs may be biased by post-mortem transportation, and the adult skeleton has implications for assessing the proposed relictual nature of Late Cretaceous eastern North American vertebrates.
Collapse
Affiliation(s)
- Chase Doran Brownstein
- Stamford Museum and Nature Center, Stamford, Connecticut, USA
- Yale University, New Haven, Connecticut, USA
| |
Collapse
|
12
|
Griffin CT, Stocker MR, Colleary C, Stefanic CM, Lessner EJ, Riegler M, Formoso K, Koeller K, Nesbitt SJ. Assessing ontogenetic maturity in extinct saurian reptiles. Biol Rev Camb Philos Soc 2020; 96:470-525. [PMID: 33289322 DOI: 10.1111/brv.12666] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 10/09/2020] [Accepted: 10/28/2020] [Indexed: 01/06/2023]
Abstract
Morphology forms the most fundamental level of data in vertebrate palaeontology because it is through interpretations of morphology that taxa are identified, creating the basis for broad evolutionary and palaeobiological hypotheses. Assessing maturity is one of the most basic aspects of morphological interpretation and provides the means to study the evolution of ontogenetic changes, population structure and palaeoecology, life-history strategies, and heterochrony along evolutionary lineages that would otherwise be lost to time. Saurian reptiles (the least-inclusive clade containing Lepidosauria and Archosauria) have remained an incredibly diverse, numerous, and disparate clade through their ~260-million-year history. Because of the great disparity in this group, assessing maturity of saurian reptiles is difficult, fraught with methodological and terminological ambiguity. We compiled a novel database of literature, assembling >900 individual instances of saurian maturity assessment, to examine critically how saurian maturity has been diagnosed. We review the often inexact and inconsistent terminology used in saurian maturity assessment (e.g. 'juvenile', 'mature') and provide routes for better clarity and cross-study coherence. We describe the various methods that have been used to assess maturity in every major saurian group, integrating data from both extant and extinct taxa to give a full account of the current state of the field and providing method-specific pitfalls, best practices, and fruitful directions for future research. We recommend that a new standard subsection, 'Ontogenetic Assessment', be added to the Systematic Palaeontology portions of descriptive studies to provide explicit ontogenetic diagnoses with clear criteria. Because the utility of different ontogenetic criteria is highly subclade dependent among saurians, even for widely used methods (e.g. neurocentral suture fusion), we recommend that phylogenetic context, preferably in the form of a phylogenetic bracket, be used to justify the use of a maturity assessment method. Different methods should be used in conjunction as independent lines of evidence when assessing maturity, instead of an ontogenetic diagnosis resting entirely on a single criterion, which is common in the literature. Critically, there is a need for data from extant taxa with well-represented growth series to be integrated with the fossil record to ground maturity assessments of extinct taxa in well-constrained, empirically tested methods.
Collapse
Affiliation(s)
- Christopher T Griffin
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
| | - Michelle R Stocker
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
| | - Caitlin Colleary
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Vertebrate Paleontology, Cleveland Museum of Natural History, 1 Wade Oval Drive, Cleveland, OH, 44106, U.S.A
| | - Candice M Stefanic
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Anatomical Sciences, Stony Brook University, 100 Nicolls Road, Stony Brook, NY, 11794, U.S.A
| | - Emily J Lessner
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Pathology and Anatomical Sciences, University of Missouri, 1 Hospital Drive, Columbia, MO, 65212, U.S.A
| | - Mitchell Riegler
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Geological Sciences, University of Florida, 241 Williamson Hall, Gainesville, FL, 32611, U.S.A
| | - Kiersten Formoso
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Earth Sciences, University of Southern California, 3651 Trousdale Pkwy, Los Angeles, CA, 90089, U.S.A
- Dinosaur Institute, Natural History Museum of Los Angeles County, 900 W Exposition Boulevard, Los Angeles, CA, 90007, U.S.A
| | - Krista Koeller
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Biology, University of Florida, 220 Bartram Hall, Gainesville, FL, 32611, U.S.A
| | - Sterling J Nesbitt
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
| |
Collapse
|
13
|
Takasaki R, Fiorillo AR, Tykoski RS, Kobayashi Y. Re-examination of the cranial osteology of the Arctic Alaskan hadrosaurine with implications for its taxonomic status. PLoS One 2020; 15:e0232410. [PMID: 32374777 PMCID: PMC7202651 DOI: 10.1371/journal.pone.0232410] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 04/14/2020] [Indexed: 11/18/2022] Open
Abstract
Hadrosaurid fossils from the Liscomb Bonebed (Prince Creek Formation, North Slope, Alaska) were the first dinosaur bones discovered from the Arctic. While the Prince Creek Formation hadrosaurids were long identified as Edmontosaurus, a member of the sub-clade Hadrosaurinae, they were recently assigned to a newly-erected taxon, Ugrunaaluk kuukpikensis. However, taxonomic status of the new taxon is ambiguous largely due to the immature nature of the specimens upon which it was based. Here we reexamine cranial elements of the Prince Creek Formation hadrosaurine in order to solve its taxonomic uncertainties. The Prince Creek Formation hadrosaurine possesses a short dorsolateral process of the laterosphenoid, one of the diagnostic characters of Edmontosaurus. The Prince Creek Formation hadrosaurine also shows affinity to Edmontosaurus regalis in the presence of a horizontal shelf of the jugal. Our morphological comparisons with other North American Edmontosaurus specimens and our phylogenetic analyses demonstrate that the Prince Creek Formation hadrosaurine should be re-assigned to Edmontosaurus. Because the Prince Creek Formation Edmontosaurus shows differences with lower latitude Edmontosaurus in a dorsoventrally short maxilla, presence of a secondary ridge on the dentary teeth, and the absence of the transverse ridge between basipterygoid processes of the basisphenoid, we consider that the Prince Creek Formation Edmontosaurus should be regarded as Edmontosaurus sp. until further discoveries of mature hadrosaurines from the Prince Creek Formation Bonebed and/or equivalently juvenile Edmontosaurus specimens from the lower latitudes allow direct comparisons. The retention of the Prince Creek Formation hadrosaurine as Edmontosaurus re-establishes a significant latitudinal distribution for this taxon. Despite the large latitudinal distribution of the taxon, the morphological disparity of Edmontosaurus is small within Hadrosaurinae. The small morphological disparity may be related to the relatively low latitudinal temperature gradient during the latest Cretaceous compared to present day, a gradient which might not have imposed significant pressure for much morphological adaptations across a broad latitudinal range.
Collapse
Affiliation(s)
- Ryuji Takasaki
- Faculty of Biosphere-Geosphere Science, Okayama University of Science, Ridaicho, Kita-ku, Okayama city, Okayama, Japan
| | | | - Ronald S. Tykoski
- Perot Museum of Nature and Science, Dallas, Texas, United States of America
| | | |
Collapse
|
14
|
Wilson JP, Ryan MJ, Evans DC. A new, transitional centrosaurine ceratopsid from the Upper Cretaceous Two Medicine Formation of Montana and the evolution of the ' Styracosaurus-line' dinosaurs. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200284. [PMID: 32431910 PMCID: PMC7211873 DOI: 10.1098/rsos.200284] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 04/06/2020] [Indexed: 06/11/2023]
Abstract
Ceratopsids are among the most ubiquitous dinosaur taxa from the Late Cretaceous terrestrial formations of the Western Interior of North America, comprising two subfamilies, Chasmosaurinae and Centrosaurinae. The Two Medicine Formation of northwestern Montana has produced numerous remains of centrosaurine dinosaurs, which represent three taxa previously considered valid: Rubeosaurus ovatus, Einiosaurus procurvicornis and Achelousaurus horneri. Here, we reassess the previous referral of specimens to Rubeousaurus ovatus and demonstrate that this taxon is represented solely by its holotype specimen, which was first diagnosed as Styracosaurus ovatus. One of the specimens previously referred to 'Rubeosaurus' ovatus instead represents a new eucentrosauran centrosaurine taxon diagnosed here, Stellasaurus ancellae gen. et sp. nov. Stellasaurus expresses a unique combination of eucentrosauran centrosaurine characters, including an elongate nasal horncore, diminutive supraorbital horncores, and a parietal bearing straight, elongate P3 processes, semi-elongate P4 processes and non-elongate P5, P6 and P7 processes. Within the stratigraphic succession of Eucentrosaura, Stellasaurus occurs intermediate to Styracosaurus albertensis and Einiosaurus, and likewise reflects intermediate morphology. Assessed within the stratigraphic, geographical, taphonomic, ontogenetic and phylogenetic framework of Unified Frames of Reference, we fail to reject the hypothesis that Stellasaurus ancellae represents a transitional taxon within an anagenetic lineage of eucentrosauran centrosaurines.
Collapse
Affiliation(s)
- John P. Wilson
- Varricchio Lab, Department of Earth Sciences, Montana State University, Bozeman, MT 59715, USA
| | - Michael J. Ryan
- Department of Earth Sciences, Carleton University, 2125 Herzberg Building, 1125 Colonel By Drive, Ottawa, OntarioCanadaK1S 5B6
- Department of Palaeobiology, Canadian Museum of Nature, PO Box 3443, Station ‘D’, Ottawa, Ontario, CanadaK1P 6P4
| | - David C. Evans
- Department of Natural History, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario, CanadaM5S 2C6
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, CanadaM5S 3B2
| |
Collapse
|
15
|
Kobayashi Y, Nishimura T, Takasaki R, Chiba K, Fiorillo AR, Tanaka K, Chinzorig T, Sato T, Sakurai K. A New Hadrosaurine (Dinosauria: Hadrosauridae) from the Marine Deposits of the Late Cretaceous Hakobuchi Formation, Yezo Group, Japan. Sci Rep 2019; 9:12389. [PMID: 31488887 PMCID: PMC6728324 DOI: 10.1038/s41598-019-48607-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 08/02/2019] [Indexed: 11/10/2022] Open
Abstract
A nearly complete skeleton of a new hadrosaurid, Kamuysaurus japonicus gen. et sp. nov., was discovered from the outer shelf deposits of the Upper Cretaceous Hakobuchi Formation of the Yezo Group in Hobetsu area of Mukawa town in Hokkaido, Japan. Kamuysaurus belongs to the sub-clade of Hadrosaurinae, Edmontosaurini, and forms a monophyly with Laiyangosaurus and Kerberosaurus from the northern Far East. Kamuysaurus has a long anterior platform for the nasofrontal sutural surface, which may indicate the presence of a small supracranial crest, similar to a sub-adult form of Brachylophosaurus based on the extension of the nasofrontal sutural surface. The Dispersal Extinction Cladogenesis analysis with the 50% Majority Rule consensus tree suggests that the clade of Kamuysaurus, Laiyangosaurus, and Kerberosaurus may have dispersed into Asia prior to the late Campanian and the potential endemism of this clade during the late Campanian and early Maastrichtian in the northern Far East. The results of both Dispersal Extinction Cladogenesis and Ancestral State Reconstruction analyses imply that the marine-influenced environment in North America during the Campanian may have played an important role for the hadrosaurid diversification in its early evolutionary history.
Collapse
Affiliation(s)
- Yoshitsugu Kobayashi
- Hokkaido University Museum, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan.
| | | | - Ryuji Takasaki
- Department of Natural History and Planetary Sciences, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan
| | - Kentaro Chiba
- Faculty of Biosphere-Geosphere Science, Okayama University of Science, Okayama, 700-0005, Japan
| | | | - Kohei Tanaka
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan
| | - Tsogtbaatar Chinzorig
- Division of Vertebrate Paleontology, Institute of Paleontology and Geology, Mongolian Academy of Sciences, Ulaanbaatar, 15160, Mongolia
| | - Tamaki Sato
- Department of Astronomy and Earth Sciences, Tokyo Gakugei University, Koganei, Tokyo, 184-8501, Japan
| | | |
Collapse
|
16
|
The Smallest Diplodocid Skull Reveals Cranial Ontogeny and Growth-Related Dietary Changes in the Largest Dinosaurs. Sci Rep 2018; 8:14341. [PMID: 30310088 PMCID: PMC6181913 DOI: 10.1038/s41598-018-32620-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 08/24/2018] [Indexed: 12/04/2022] Open
Abstract
Sauropod dinosaurs were the largest terrestrial vertebrates; yet despite a robust global fossil record, the paucity of cranial remains complicates attempts to understand their paleobiology. An assemblage of small diplodocid sauropods from the Upper Jurassic Morrison Formation of Montana, USA, has produced the smallest diplodocid skull yet discovered. The ~24 cm long skull is referred to cf. Diplodocus based on the presence of several cranial and vertebral characters. This specimen enhances known features of early diplodocid ontogeny including a short snout with narrow-crowned teeth limited to the anterior portion of the jaws and more spatulate teeth posteriorly. The combination of size plus basal and derived character expression seen here further emphasizes caution when naming new taxa displaying the same, as these may be indicative of immaturity. This young diplodocid reveals that cranial modifications occurred throughout growth, providing evidence for ontogenetic dietary partitioning and recapitulation of ancestral morphologies.
Collapse
|
17
|
Gates TA, Tsogtbaatar K, Zanno LE, Chinzorig T, Watabe M. A new iguanodontian (Dinosauria: Ornithopoda) from the Early Cretaceous of Mongolia. PeerJ 2018; 6:e5300. [PMID: 30083450 PMCID: PMC6078070 DOI: 10.7717/peerj.5300] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 07/03/2018] [Indexed: 11/20/2022] Open
Abstract
We describe a new iguanodontian ornithopod, Choyrodon barsboldi gen. et sp. nov. from the Albian-aged Khuren Dukh Formation of Mongolia based on several partial skeletons interpreted to represent a subadult growth stage based on osteohistological features. This new taxon is diagnosed by many autapomorphies of the maxilla, nasal, lacrimal, opisthotic, predentary, and surangular. Choyrodon displays an unusual combination of traits, possessing an open antorbital fenestra (a primitive ornithopod trait) together with derived features such as a downturned dentary and enlarged narial fenestra. Histological imaging suggests that the type specimen of Choyrodon would have been a subadult at the time of death. Phylogenetic analysis of two different character matrices do not posit Choyrodon to be the sister taxon or to be more primitive than the iguanodontian Altirhinus kurzanovi, which is found in the same formation. The only resolved relationship of this new taxon is that it was hypothesized to be a sister-taxon with the North American species Eolambia caroljonesa. Though discovered in the same formation and Choyrodon being smaller-bodied than Altirhinus, it does not appear that the former species is an ontogimorph of the latter. Differences in morphology and results of the phylogenetic analyses support their distinction although more specimens of both species will allow better refinement of their uniqueness.
Collapse
Affiliation(s)
- Terry A Gates
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA.,Paleontology Unit, North Carolina Museum of Natural Sciences, Raleigh, NC, USA
| | - Khishigjav Tsogtbaatar
- Department of Paleontology, Institute of Paleontology and Geology, Mongolian Academy of Sciences, Ulaanbataar, Mongolia
| | - Lindsay E Zanno
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA.,Paleontology Unit, North Carolina Museum of Natural Sciences, Raleigh, NC, USA
| | - Tsogtbaatar Chinzorig
- Department of Paleontology, Institute of Paleontology and Geology, Mongolian Academy of Sciences, Ulaanbataar, Mongolia.,Department of Natural History and Earth Sciences, Faculty of Sciences, Hokkaido University, Hokkaido University Museum, Sapporo, Japan
| | - Mahito Watabe
- School of International Liberal Studies, Waseda University, Tokyo, Japan
| |
Collapse
|
18
|
Prieto-Marquez A, Guenther MF. Perinatal specimens of Maiasaura from the Upper Cretaceous of Montana (USA): insights into the early ontogeny of saurolophine hadrosaurid dinosaurs. PeerJ 2018; 6:e4734. [PMID: 29785343 PMCID: PMC5960587 DOI: 10.7717/peerj.4734] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 04/18/2018] [Indexed: 11/20/2022] Open
Abstract
Perinatal specimens of hadrosaurids discovered in the late 1970’s by field crews from Princeton University were significant in providing evidence of the early ontogenetic stages in North American dinosaurs. These specimens from the Campanian (Upper Cretaceous) Two Medicine Formation of Montana consist of over a dozen skeletons referable to the saurolophine hadrosaurid Maiasaura peeblesorum, but never fully figured or described. Here, we provide a more complete documentation of the morphology of these specimens, along with an examination of variation during a large span of the development of saurolophine hadrosaurids. Many ontogenetic changes in the available facial and mandibular elements are associated with the progressive elongation of the preorbital region of the skull and mandible. In the postcranium, limb bones change nearly isometrically, with exception of certain elements of the forelimb. Some cranial and postcranial characters commonly used for inferring hadrosaurid phylogenetic relationships remain invariable during the ontogeny of M. peeblesorum. This indicates that early ontogenetic stages may still provide a limited amount of character information useful for systematics and phylogenetic inference.
Collapse
Affiliation(s)
- Albert Prieto-Marquez
- Mesozoic Research, Catalan Institute of Paleontology Miquel Crusafont, Sabadell, Spain
| | | |
Collapse
|
19
|
Fowler DW. Revised geochronology, correlation, and dinosaur stratigraphic ranges of the Santonian-Maastrichtian (Late Cretaceous) formations of the Western Interior of North America. PLoS One 2017; 12:e0188426. [PMID: 29166406 PMCID: PMC5699823 DOI: 10.1371/journal.pone.0188426] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 11/01/2017] [Indexed: 11/20/2022] Open
Abstract
Interbasinal stratigraphic correlation provides the foundation for all consequent continental-scale geological and paleontological analyses. Correlation requires synthesis of lithostratigraphic, biostratigraphic and geochronologic data, and must be periodically updated to accord with advances in dating techniques, changing standards for radiometric dates, new stratigraphic concepts, hypotheses, fossil specimens, and field data. Outdated or incorrect correlation exposes geological and paleontological analyses to potential error. The current work presents a high-resolution stratigraphic chart for terrestrial Late Cretaceous units of North America, combining published chronostratigraphic, lithostratigraphic, and biostratigraphic data. 40Ar / 39Ar radiometric dates are newly recalibrated to both current standard and decay constant pairings. Revisions to the stratigraphic placement of most units are slight, but important changes are made to the proposed correlations of the Aguja and Javelina formations, Texas, and recalibration corrections in particular affect the relative age positions of the Belly River Group, Alberta; Judith River Formation, Montana; Kaiparowits Formation, Utah; and Fruitland and Kirtland formations, New Mexico. The stratigraphic ranges of selected clades of dinosaur species are plotted on the chronostratigraphic framework, with some clades comprising short-duration species that do not overlap stratigraphically with preceding or succeeding forms. This is the expected pattern that is produced by an anagenetic mode of evolution, suggesting that true branching (speciation) events were rare and may have geographic significance. The recent hypothesis of intracontinental latitudinal provinciality of dinosaurs is shown to be affected by previous stratigraphic miscorrelation. Rapid stepwise acquisition of display characters in many dinosaur clades, in particular chasmosaurine ceratopsids, suggests that they may be useful for high resolution biostratigraphy.
Collapse
|
20
|
Woodruff DC, Foster JR. The first specimen of Camarasaurus (Dinosauria: Sauropoda) from Montana: The northernmost occurrence of the genus. PLoS One 2017; 12:e0177423. [PMID: 28562606 PMCID: PMC5451207 DOI: 10.1371/journal.pone.0177423] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Accepted: 03/13/2017] [Indexed: 11/18/2022] Open
Abstract
A partial skeleton from the Little Snowy Mountains of central Montana is the first referable specimen of the Morrison Formation macronarian sauropod Camarasaurus. This specimen also represents the northernmost occurrence of a sauropod in the Morrison. Histological study indicates that, although the specimen is relatively small statured, it is skeletally mature; this further emphasizes that size is not a undeviating proxy to maturity in dinosaurs, and that morphologies associated with an individual’s age and stature may be more nebulous in sauropods.
Collapse
Affiliation(s)
- D. Cary Woodruff
- Great Plains Dinosaur Museum and Field Station, Malta, Montana, United States of America
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
- Royal Ontario Museum, Toronto, Ontario, Canada
- * E-mail:
| | | |
Collapse
|
21
|
Arbour VM, Evans DC. A new ankylosaurine dinosaur from the Judith River Formation of Montana, USA, based on an exceptional skeleton with soft tissue preservation. ROYAL SOCIETY OPEN SCIENCE 2017; 4:161086. [PMID: 28573004 PMCID: PMC5451805 DOI: 10.1098/rsos.161086] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 04/11/2017] [Indexed: 06/07/2023]
Abstract
The terrestrial Judith River Formation of northern Montana was deposited over an approximately 4 Myr interval during the Campanian (Late Cretaceous). Despite having been prospected and collected continuously by palaeontologists for over a century, few relatively complete dinosaur skeletons have been recovered from this unit to date. Here we describe a new genus and species of ankylosaurine dinosaur, Zuul crurivastator, from the Coal Ridge Member of the Judith River Formation, based on an exceptionally complete and well-preserved skeleton (ROM 75860). This is the first ankylosaurin skeleton known with a complete skull and tail club, and it is the most complete ankylosaurid ever found in North America. The presence of abundant soft tissue preservation across the skeleton, including in situ osteoderms, skin impressions and dark films that probably represent preserved keratin, make this exceptional skeleton an important reference for understanding the evolution of dermal and epidermal structures in this clade. Phylogenetic analysis recovers Zuul as an ankylosaurin ankylosaurid within a clade of Dyoplosaurus and Scolosaurus, with Euoplocephalus being more distantly related within Ankylosaurini. The occurrence of Z. crurivastator from the upper Judith River Formation fills a gap in the ankylosaurine stratigraphic and geographical record in North America, and further highlights that Campanian ankylosaurines were undergoing rapid evolution and stratigraphic succession of taxa as observed for Laramidian ceratopsids, hadrosaurids, pachycephalosaurids and tyrannosaurids.
Collapse
Affiliation(s)
- Victoria M. Arbour
- Department of Palaeobiology, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario, Canada, M5S 2C6
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, CanadaM5S 3B2
| | - David C. Evans
- Department of Palaeobiology, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario, Canada, M5S 2C6
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, CanadaM5S 3B2
| |
Collapse
|
22
|
Xing H, Mallon JC, Currie ML. Supplementary cranial description of the types of Edmontosaurus regalis (Ornithischia: Hadrosauridae), with comments on the phylogenetics and biogeography of Hadrosaurinae. PLoS One 2017; 12:e0175253. [PMID: 28384240 PMCID: PMC5383305 DOI: 10.1371/journal.pone.0175253] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 03/22/2017] [Indexed: 11/18/2022] Open
Abstract
The cranial anatomy of the flat-skulled hadrosaurine Edmontosaurus regalis (Ornithischia: Hadrosauridae) is extensively described here, based on the holotype and paratype collected from the middle part of the Horseshoe Canyon Formation in southern Alberta. Focus is given to previously undocumented features of ontogenetic and phylogenetic importance. This description facilitates overall osteological comparisons between E. regalis and other hadrosaurids (especially E. annectens), and revises the diagnosis of E. regalis, to which a new autapomorphy (the dorsal half of the jugal anterior process bearing a sharp posterolateral projection into the orbit) is added. We consider the recently named Ugrunaaluk kuukpikensis from the upper Campanian/lower Maastrichtian of Alaska a nomen dubium, and conservatively regard the Alaskan material as belonging to Edmontosaurus sp.. A phylogenetic analysis of Hadrosauroidea using maximum parsimony further corroborates the sister-taxon relationship between E. regalis and E. annectens. In the strict consensus tree, Hadrosaurus foulkii occurs firmly within the clade comprising all non-lambeosaurine hadrosaurids, supporting the taxonomic scheme that divides Hadrosauridae into Hadrosaurinae and Lambeosaurinae. Within Edmontosaurini, Kerberosaurus is posited as the sister taxon to the clade of Shantungosaurus + Edmontosaurus. The biogeographic reconstruction of Hadrosaurinae in light of the time-calibrated cladogram and probability calculation of ancestral areas for all internal nodes reveals a significantly high probability for the North American origin of the clade. However, the Laramidia–Appalachia dispersals around the Santonian–Campanian boundary, inferred from the biogeographic scenario for the North American origin of Hadrosaurinae, are in conflict with currently accepted paleogeographic models. By contrast, the Asian origin of Hadrosaurinae with its relatively low probability resulting from the biogeographic analysis is worth seriously considering, despite the lack of fossil material from the Santonian and lower Campanian of Asia. Extra fossil collecting in appropriate geographic locations and stratigraphic intervals of Asia and Europe will help to clarify the biogeographic dynamics of hadrosaurine dinosaurs in the near future.
Collapse
Affiliation(s)
- Hai Xing
- Beijing Museum of Natural History, Beijing Academy of Science and Technology, Beijing, China
- * E-mail:
| | - Jordan C. Mallon
- Palaeobiology, Canadian Museum of Nature, Ottawa, Ontario, Canada
| | | |
Collapse
|
23
|
Carr TD, Varricchio DJ, Sedlmayr JC, Roberts EM, Moore JR. A new tyrannosaur with evidence for anagenesis and crocodile-like facial sensory system. Sci Rep 2017; 7:44942. [PMID: 28358353 PMCID: PMC5372470 DOI: 10.1038/srep44942] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 02/14/2017] [Indexed: 11/13/2022] Open
Abstract
A new species of tyrannosaurid from the upper Two Medicine Formation of Montana supports the presence of a Laramidian anagenetic (ancestor-descendant) lineage of Late Cretaceous tyrannosaurids. In concert with other anagenetic lineages of dinosaurs from the same time and place, this suggests that anagenesis could have been a widespread mechanism generating species diversity amongst dinosaurs, and perhaps beyond. We studied the excellent fossil record of the tyrannosaurid to test that hypothesis. Phylogenetic analysis places this new taxon as the sister species to Daspletosaurus torosus. However, given their close phylogenetic relationship, geographic proximity, and temporal succession, where D. torosus (~76.7-75.2 Ma) precedes the younger new species (~75.1-74.4 Ma), we argue that the two forms most likely represent a single anagenetic lineage. Daspletosaurus was an important apex predator in the late Campanian dinosaur faunas of Laramidia; its absence from later units indicates it was extinct before Tyrannosaurus rex dispersed into Laramidia from Asia. In addition to its evolutionary implications, the texture of the facial bones of the new taxon, and other derived tyrannosauroids, indicates a scaly integument with high tactile sensitivity. Most significantly, the lower jaw shows evidence for neurovasculature that is also seen in birds.
Collapse
Affiliation(s)
- Thomas D. Carr
- Carthage College, 2001 Alford Park Drive, Kenosha, WI 53140, USA
| | - David J. Varricchio
- Department of Earth Sciences, Montana State University, P.O. Box 173480, Bozeman, MT 59717-3480, USA
| | - Jayc C. Sedlmayr
- Louisiana State University Health Sciences Centre - School of Medicine, 1901 Perdido Street, New Orleans, LA 70112, USA
| | - Eric M. Roberts
- Geosciences, College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
| | - Jason R. Moore
- Honors College, University of New Mexico, Albuquerque, NM 87131, USA
| |
Collapse
|
24
|
Mallon JC, Ott CJ, Larson PL, Iuliano EM, Evans DC. Spiclypeus shipporum gen. et sp. nov., a Boldly Audacious New Chasmosaurine Ceratopsid (Dinosauria: Ornithischia) from the Judith River Formation (Upper Cretaceous: Campanian) of Montana, USA. PLoS One 2016; 11:e0154218. [PMID: 27191389 PMCID: PMC4871577 DOI: 10.1371/journal.pone.0154218] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 04/11/2016] [Indexed: 11/25/2022] Open
Abstract
This study reports on a new ceratopsid, Spiclypeus shipporum gen et sp. nov., from the lower Coal Ridge Member of the Judith River Formation in Montana, USA, which dates to ~76 Ma (upper Campanian). The species is distinguished by rugose dorsal contacts on the premaxillae for the nasals, laterally projecting postorbital horncores, fully fused and anteriorly curled P1 and P2 epiparietals, and a posterodorsally projecting P3 epiparietal. The holotype specimen is also notable for its pathological left squamosal and humerus, which show varied signs of osteomyelitis and osteoarthritis. Although the postorbital horncores of Spiclypeus closely resemble those of the contemporaneous ‘Ceratops’, the horncores of both genera are nevertheless indistinguishable from those of some other horned dinosaurs, including Albertaceratops and Kosmoceratops; ‘Ceratops’ is therefore maintained as a nomen dubium. Cladistic analysis recovers Spiclypeus as the sister taxon to the clade Vagaceratops + Kosmoceratops, and appears transitional in the morphology of its epiparietals. The discovery of Spiclypeus adds to the poorly known dinosaur fauna of the Judith River Formation, and suggests faunal turnover within the formation.
Collapse
Affiliation(s)
- Jordan C. Mallon
- Palaeobiology, Canadian Museum of Nature, PO Box 3443 Station “D”, Ottawa, Ontario, K1P 6P4, Canada
- * E-mail:
| | - Christopher J. Ott
- Independent Researcher, PO Box 1515, Appleton, Wisconsin, 54912, United States of America
| | - Peter L. Larson
- Black Hills Institute, 217 Main Street, Hill City, South Dakota, 57745, United States of America
| | - Edward M. Iuliano
- Kadlec Medical Center, 888 Swift Boulevard, Richland, Washington, 99352, United States of America
| | - David C. Evans
- Department of Natural History, Royal Ontario Museum, 100 Queen’s Park, Toronto, Ontario, M5S 2C6, Canada
| |
Collapse
|
25
|
Prieto-Márquez A, Erickson GM, Ebersole JA. Anatomy and osteohistology of the basal hadrosaurid dinosaur Eotrachodon from the uppermost Santonian (Cretaceous) of southern Appalachia. PeerJ 2016; 4:e1872. [PMID: 27114863 PMCID: PMC4841272 DOI: 10.7717/peerj.1872] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 03/09/2016] [Indexed: 11/20/2022] Open
Abstract
The cranial and postcranial anatomy of the basal hadrosaurid dinosaur Eotrachodon orientalis, from the uppermost Santonian of southern Appalachia (southeastern U.S.A.), is described in detail. This animal is the only known pre-Campanian non-lambeosaurine hadrosaurid, and the most complete hadrosauroid known from Appalachia. E. orientalis possesses a mosaic of plesiomorphic and derived characters in the context of Hadrosauroidea. Characters shared with basal hadrosauroids include a short and sloping maxillary ectopterygoid shelf, caudally prominent maxillary jugal process, one functional tooth per alveolus on the maxillary occlusal plane, a jugal rostral process with a shallow caudodorsal margin and medioventrally facing articular facet, a vertical dentary coronoid process with a poorly expanded apex, and tooth crowns with accessory ridges. Derived characters shared with other hadrosaurids include a circumnarial depression compartmented into three fossae (as in brachylophosaurins and Edmontosaurus), a thin everted premaxillary oral margin (as in Gryposaurus, Prosaurolophus, and Saurolophus), and a maxilla with a deep and rostrocaudally extensive rostrodorsal region with a steeply sloping premaxillary margin (as in Gryposaurus). Eotrachodon orientalis differs primarily from the other hadrosauroid from the Mooreville Chalk of Alabama, Lophorhothon atopus, in having a slender and crestless nasal whose caudodorsal margin is not invaded by the circumnarial depression. Hadrosaurus foulkii, the only other known hadrosaurid from Appalachia, is distinct from E. orientalis in having dentary teeth lacking accessory ridges and a dorsally curved shaft of the ischium. A histological section of the tibia of the E. orientalis holotype (MSC 7949) suggests that this individual was actively growing at the time of death and, thus, had the potential to become a larger animal later in development.
Collapse
Affiliation(s)
| | - Gregory M Erickson
- Department of Biological Science, Florida State University , Tallahassee, Florida , USA
| | | |
Collapse
|